commit	b6883b3b87ae731cdb513310d64f3ea771c8afb5	[log] [tgz]
author	Android Build Coastguard Worker <android-build-coastguard-worker@google.com>	Mon Dec 20 11:04:40 2021 +0000
committer	Android Build Coastguard Worker <android-build-coastguard-worker@google.com>	Mon Dec 20 11:04:40 2021 +0000
tree	a37d77a527c577f11a2c00f84694c9fd47b5617b
parent	c69bef84aedd1242ed637501db37eb86ff8bab06 [diff]
parent	011d805a61cf0d8c148b125c92187ef3f9b3ba03 [diff]

tree: a37d77a527c577f11a2c00f84694c9fd47b5617b

README.md

itoa

This crate provides fast functions for printing integer primitives to an io::Write or a fmt::Write. The implementation comes straight from libcore but avoids the performance penalty of going through fmt::Formatter.

See also dtoa for printing floating point primitives.

Version requirement: rustc 1.0+

[dependencies]
itoa = "0.4"

Performance (lower is better)

performance

Examples

use std::{fmt, io};

fn demo_itoa_write() -> io::Result<()> {
    // Write to a vector or other io::Write.
    let mut buf = Vec::new();
    itoa::write(&mut buf, 128u64)?;
    println!("{:?}", buf);

    // Write to a stack buffer.
    let mut bytes = [0u8; 20];
    let n = itoa::write(&mut bytes[..], 128u64)?;
    println!("{:?}", &bytes[..n]);

    Ok(())
}

fn demo_itoa_fmt() -> fmt::Result {
    // Write to a string.
    let mut s = String::new();
    itoa::fmt(&mut s, 128u64)?;
    println!("{}", s);

    Ok(())
}

The function signatures are:

fn write<W: io::Write, V: itoa::Integer>(writer: W, value: V) -> io::Result<usize>;

fn fmt<W: fmt::Write, V: itoa::Integer>(writer: W, value: V) -> fmt::Result;

where itoa::Integer is implemented for i8, u8, i16, u16, i32, u32, i64, u64, i128, u128, isize and usize. 128-bit integer support requires rustc 1.26+ and the i128 feature of this crate enabled.

The write function is only available when the std feature is enabled (default is enabled). The return value gives the number of bytes written.

itoa

Performance (lower is better)

Examples

License